posix man page for hypotf

HYPOT(P)						     POSIX Programmer's Manual							  HYPOT(P)

NAME
       hypot, hypotf, hypotl - Euclidean distance function

SYNOPSIS
       #include <math.h>

       double hypot(double x, double y);
       float hypotf(float x, float y);
       long double hypotl(long double x, long double y);

DESCRIPTION
       These functions shall compute the value of the square root of x**2+ y**2 without undue overflow or underflow.

       An  application	wishing  to check for error situations should set errno to zero and call feclearexcept(FE_ALL_EXCEPT) before calling these
       functions.  On return, if errno is non-zero or fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero,  an  error
       has occurred.

RETURN VALUE
       Upon successful completion, these functions shall return the length of the hypotenuse of a right-angled triangle with sides of length x and
       y.

       If the correct value would cause overflow, a range error shall occur and hypot(), hypotf(), and hypotl() shall  return  the  value  of  the
       macro HUGE_VAL, HUGE_VALF, and HUGE_VALL, respectively.

       If x or y is +-Inf, +Inf shall be returned (even if one of x or y is NaN).

       If x or y is NaN, and the other is not +-Inf, a NaN shall be returned.

       If both arguments are subnormal and the correct result is subnormal, a range error may occur and the correct result is returned.

ERRORS
       These functions shall fail if:

       Range Error
	      The result overflows.

       If  the	integer  expression  (math_errhandling	&  MATH_ERRNO) is non-zero, then errno shall be set to [ERANGE]. If the integer expression
       (math_errhandling & MATH_ERREXCEPT) is non-zero, then the overflow floating-point exception shall be raised.

       These functions may fail if:

       Range Error
	      The result underflows.

       If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, then errno shall be set  to  [ERANGE].  If  the  integer	expression
       (math_errhandling & MATH_ERREXCEPT) is non-zero, then the underflow floating-point exception shall be raised.

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       hypot(x,y), hypot(y,x), and hypot(x, -y) are equivalent.

       hypot(x, +-0) is equivalent to fabs(x).

       Underflow only happens when both x and y are subnormal and the (inexact) result is also subnormal.

       These functions take precautions against overflow during intermediate steps of the computation.

       On  error,  the	expressions  (math_errhandling & MATH_ERRNO) and (math_errhandling & MATH_ERREXCEPT) are independent of each other, but at
       least one of them must be non-zero.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       feclearexcept() , fetestexcept() , isnan() , sqrt() , the Base Definitions volume of IEEE Std 1003.1-2001, Section 4.18, Treatment of Error
       Conditions for Mathematical Functions, <math.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol-
       ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
       Electrical  and	Electronics  Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE
       and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can  be  obtained
       online at http://www.opengroup.org/unix/online.html .

IEEE
/The Open Group						       2003								  HYPOT(P)